The present invention relates to an information processing technique, and more particularly to a text mining technique which divides document data into individual words and the like, and analyzes frequency of appearance, mutual relationship, and the like, of the individual words.
In order to develop a product that is appreciated by customers, it is necessary to stand in the position of the customer who actually purchases and uses the product, in other words, to develop products through an “in-market” orientation, instead of planning and developing from the conventional product output perspective, so as to differentiate the product from competitors' products and increase product attractiveness. For the purpose of resolving this problem, many companies conduct marketing activities by performing market surveys to collect customer opinions and analyzing the customer opinions thus collected in order to comprehend trends in the market and customer needs, or to define target customers. Companies also use product and service complaints which are sent to their call centers, along with customer opinions that are written on the company web site discussion boards, as important information for comprehending customer needs.
The above-described marketing activities and customer opinions that are collected at call centers (VOC: Voice of Customer) involve much textual data in the form of natural language text, rather than numerical values. For example, the entries in the free comment sections of questionnaire surveys, and the complaints received at call centers and the like, are written in textual format. Because of this, in order to grasp customer needs and market trends, it is necessary to accurately analyze data in text format (text data). As a method of analyzing voluminous electronic text data, a method is known that is referred to as text mining to which data mining techniques for analyzing numerical data are applied.
For example, Japanese Patent Laid-Open Publication No. 2004-21445 (hereinafter, referred to as Patent Document 1) discloses a text mining system for objectively presenting voluminous text data. The text mining system disclosed in Patent Document 1 adopts a quantification technique that counts frequency of appearance of specific individual words contained in text that is being searched, and a quantification technique that counts the number of documents containing words similar to these specific individual words.
Japanese Patent Laid-Open Publication No. 2005-115468 (hereinafter, referred to as Patent Document 2) discloses a technique that creates a conceptual dictionary for each product being analyzed, then cross-compares text being evaluated against a database containing predefined patterns of words indicating positive and negative evaluations, and then calculates the levels of satisfaction and dissatisfaction expressed in the text.